Recyclable liner for label assembly

ABSTRACT

In accordance with the present application, there is provided a release liner and method of preparing a liner for a label assembly. The release liner includes paper having a first side that does not have a machine finish or gloss finish or a coating; and a silicone treatment applied to the first side of the paper. The method of preparing a liner for a label assembly includes applying a coat of silicone to a paper at a side of the paper that does not have a machine finish or gloss finish and is otherwise uncoated; and curing the silicone. The release liner includes paper having a silicone coat weight of 0.5 lb/ream or less.

RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.16/098,631 filed on Nov. 2, 2018 and claims priority to U.S. provisionalpatent application No. 62/332,006 filed on May 5, 2016, the contents ofboth are herein incorporated by reference.

FIELD

The present application relates to a label assembly and, moreparticularly, to a pressure-sensitive label having a recyclable linerand methods for manufacturing such liners and labels.

BACKGROUND

Pressure sensitive labels are commonly applied to various products toidentify information associated with the product. Such labels are usedin numerous environments to provide a variety of functions including,for example, identifying the source or destination of goods, identifyinga price associated with goods, identifying nutritional informationassociated with a food product, etc.

Typically, pressure sensitive labels include a top layer which isconfigured for being printed upon. The top layer is coated with adhesiveon a bottom side. The label may not be used immediately following itsmanufacture and so a release liner is placed on the other side of theadhesive to prevent the adhesive from unintentionally sticking to otheritems. The release liner is coated with a silicone release agent toallow the release liner to be easily removed from the adhesive when auser is ready to put the label to use.

Pressure sensitive labels are commonly manufactured using a machinefinished paper product or super calandered kraft (SCK) paper for therelease liner. That is, the paper is processed to provide a smoothsurface on at least one side of the paper. Silicone is then applied tothe finished side of the paper that will form the release liner. Thepaper's smooth surface prevents the silicone from soaking into thefibers of the paper and the silicone is effectively layered on top ofthe paper. That is, the smooth finish prevents the silicone frommigrating into the paper itself and so the silicone forms a layer on topof the paper. Then, an adhesive is attached to the label using atransfer coating process. More particularly, the adhesive is applied tothe silicone layer of the release liner. The release liner and theadhesive are then passed through a dryer which removes the water fromthe adhesive. The adhesive is then “transferred” to the back of the facesheet of the label itself. More particularly, the liner with theadhesive is laminated to the back of the face sheet by layering the facesheet on the exposed side of the adhesive. The face sheet is not treatedwith silicone and so the adhesive adheres better to the face sheet thanthe silicone treated liner and the adhesive effectively migrates to theback of the face sheet.

Typical municipal recycling facilities are not equipped to recyclerelease liners of the type described above. More particularly, thesilicone release agent may need to be scraped off the release liner topermit recycling. Since this process is difficult, used release linersare typically sent to the landfill.

While this problem has been recognized for some time, previous solutionsto this problem have been inadequate. More specifically, attempts tosolve this issue have led to the development of liner-less labels. Theselabels do not have a release liner and typically have a silicone releaseagent applied to the printable side of the top layer to allow the labelsto be released from the roll. The disadvantages to this approach arenumerous. For example, since the labels do not have a base layer (i.e. aliner), die cut shapes are not possible.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made, by way of example, to the accompanyingdrawings which show example embodiments of the present application, andin which:

FIG. 1 shows a perspective view of a label assembly in accordance withexample embodiments of the present disclosure;

FIG. 2 shows a side view of the label assembly of FIG. 1;

FIG. 3 shows a top view of a die cut label assembly in accordance withexample embodiments of the present disclosure;

FIG. 4 is a perspective view of a label assembly that includes a singlelabel in accordance with example embodiments of the present disclosure;and

FIG. 5 is a flowchart of a method for manufacturing a label assembly inaccordance with example embodiments of the present disclosure.

Similar reference numerals may have been used in different figures todenote similar components.

DETAILED DESCRIPTION

In accordance with the present application, there is provided a labelassembly. The label assembly includes a top layer having a front sideand a back side and an adhesive covering the entirety of the back sideof the top layer. The label assembly also includes a silicone-treatedliner contacting the adhesive to sandwich the adhesive between the toplayer and the liner. The silicone-treated liner includes paper having asilicone coat weight of 0.5 lb/ream or less.

In another aspect, there is provided a method of preparing a labelassembly. The method includes: forming a liner by applying a coat ofsilicone to a paper, the silicone being applied at a coat weight of 0.5lb/ream or less; applying an adhesive directly to a top layer; andlaminating the liner with the silicone to the top layer using theadhesive.

In yet another aspect, there is provided a silicone-treated liner. Thesilicone-treated liner includes paper having a silicone coat weight of0.5 lb/ream or less.

In yet another aspect, there is provided a method of preparing a liner.The method includes: applying silicone at a side of a paper at a coatweight of 0.5 lb/ream or less.

Reference is first made to FIG. 1 and FIG. 2. FIG. 1 shows a perspectiveview of a label assembly 100 and FIG. 2 shows a side view of the labelassembly 100. The label assembly 100 includes a plurality of pressuresensitive labels 110. The label assembly 100 includes a top layer 102.In the example illustrated, the top layer 102 is a label sheet whichincludes a plurality of pressure-sensitive label regions, eachassociated with a separate label 110. More particularly, the examplelabel sheet includes nine label regions, each associated with a separatelabel 110. The number of labels provided on the label sheet may,however, be different in other embodiments.

The top layer 102 has a front side 104 and a back side opposite thefront side. The front side 104 may be configured for receiving a printedlayer, such as ink. Accordingly, the front side of the top layer 102 mayinclude indicia printed thereon. Such indicia may be, for example, agraphic or text, which may be printed using ink. For example, in someembodiments, a logo may be printed on the label. In some embodiments,pricing information, nutritional information (e.g., associated with afood product), shipping information (such as a recipient or sender'saddress), or other information may be printed on the front side 104 ofthe top layer 102. The back side, which is not shown in FIG. 1 or FIG.2, is parallel to the front side.

The label assembly 100 may, in at least some embodiments, be distributedas a blank label. That is, in some embodiments, the top layer 102 maynot have indicia printed thereon when the label is distributed; the toplayer 102 may be printed on or written on after manufacture (e.g. by anend user). The top layer 102 may also be referred to as a face sheet.

The top layer 102 is paper-based and may have a paper density betweenfifty and one hundred and fifty grams per square meter (GSM). In anembodiment, the top layer 102 is constructed of 75 GSM paper. The toplayer 102 may be a film or plastic-based paper in other embodiments. Inan embodiment, the top layer 102 is uncoated paper.

The label assembly 100 also includes an adhesive 106. In someembodiments, the adhesive is a repositionable adhesive. Therepositionable adhesive is a microsphere adhesive which allows forrepositioning of the label due to the use of small particles. Therepositionable adhesive is a low-tack pressure-sensitive adhesive. Forexample, in some embodiments the adhesive is one that will provide apeel adhesion of between 80 and 204 gms if it were case directly onto 1millimeter thickness polyester film and when tested on #304 stainlesssteel.

The adhesive may use particles (which may also be referred to asspheres) between 10 and 250 microns. In at least some embodiments, theadhesive may be of the type commonly used on Post-it™ notes. Theadhesive may be of the type described in U.S. Pat. No. 3,691,140 whichwas filed Mar. 9, 1970 by Spencer Ferguson Silver and which isincorporated herein by reference.

The adhesive is applied to the back side of the top layer 102. Moreparticularly, the adhesive 106 covers the entirety of the back side ofthe top layer 102. In at least some embodiments, the adhesive is appliedto the back side of the top layer 102. The application of the adhesive106 may be performed, in at least some embodiments, using a roller. Eachlabel 110 that is provided by the top layer 102 has a back side that isentirely coated by the adhesive such that all portions of the back sideare sticky. That is, the back side of each label region of the top layerdirectly contacts the adhesive 106.

The label assembly also includes a release liner 108, which willgenerally be referred to as a liner 108 herein. The liner 108 directlycontacts the adhesive 106 at a side of the adhesive that is opposite theside that contacts the top layer 102. The liner contacts the entirety ofa side of the adhesive. Accordingly, the liner 108 effectivelysandwiches the adhesive between the top layer and the liner; theadhesive acts as a middle layer and the liner 108 acts as a bottomlayer. The adhesive 106 and the liner 108 are the only two layers thatare below the top layer 102; the adhesive 106 is the only layer betweenthe liner 108 and the top layer 102.

The liner 108 includes silicone to impart release from the adhesive 106.The silicone is applied to the side of the liner that is to contact theadhesive 106. The release liner 108 is specially treated with siliconeto allow the liner 108 to be recycled after use. This silicone isapplied at a coat weight that is significantly less than the coat weightof traditional silicone-coated release liners. For example, typicalsilicone release liners use a silicone coat weight of approximately 1.0to 1.2 lb/ream. In contrast, in at least some embodiments, the coatweight of the silicone in the release liner 108 used in accordance withthe examples described herein is less than 0.5 lb/ream. In someembodiments, the coat weight of the silicone may be less than 0.3lb/ream.

The coat weight of the silicone is sufficient to provide adequaterelease capabilities. It has been found that silicone coat weights aslow as 0.22 lb/ream can provide sufficient release capabilities when theadhesive is a low tack adhesive. In some embodiments and with someadhesives, a coat weight of 0.15 lb/ream may provide sufficient releasefrom the adhesive. Accordingly, in some embodiments, the coat weight ofthe silicone is 0.15 lb/ream or greater

The liner 108 is a paper-based liner. That is, the liner 108 isconstructed of paper, allowing for easy recycling of the liner 108. Theliner has a paper density sufficient to allow the liner 108 to beremoved without tearing. In at least some embodiments, the liner isconstructed of a paper having a paper density greater between 50 and 150grams per square meter. In one embodiment, uncoated 75 GSM paper isused.

In at least some embodiments, unlike traditional silicone-releaseliners, the paper used for the liner 108 is not a machine finished paperproduct or a super calandered kraft (SCK) paper. The paper used for theliner 108 may not have a side that has been finished to be smooth. Thatis, the silicone of the liner 108 is applied at a surface of the paper108 which is porous since the surface has not been machine finished. Insome embodiments, the paper may be bond paper (e.g., standard copypaper). Bond paper is a high quality durable writing paper similar tobank paper but having a weight greater than 50 g/m². By using suchpaper, the silicone is absorbed into the liner 108 and bonds with thefibers in the paper. That is, since the silicone (which is applied tothe paper in liquid form) is not applied to a surface which has beenfinished with a smooth, glossy finish (as is done with traditionaltechniques), the silicone is absorbed into the paper rather than layeredon top of the paper. The resulting liner 108 looks and feels likeordinary paper and it is difficult to distinguish the liner 108 from anordinary piece of paper. As a result, a recycling facility processingthe liner 108 can easily determine that the liner 108 is one that can berecycled. This can help to prevent a recycling depot from erroneouslycategorizing the liner 108 as a non-recyclable during sorting.

A liner 108 having such properties has been found to be recyclable usingordinary paper recycling techniques. That is, unlike traditionalsilicone-coated liners, the liner can be recycled without specialhandling precautions. For example, as noted above, the silicone ontraditional silicone-coated liners is sometimes scraped from such linersso that they can be recycled. In contrast, the liner of the presentapplication does not need such processing.

The liner 108 has an external side (i.e., bottom side) opposite the sideof the liner that contacts the adhesive. The external side is alsouncoated in an embodiment and does not contact any adhesive. In someembodiments, the label assembly may be provided on a roll, in which casethe external side of the liner contacts the top layer of another portionof the roll.

The liner 108 is a single-layer liner.

In the embodiment of FIGS. 1 and 2, the top layer 102 is butt cut toproduce a plurality of butt-cut labels 110. Butt cut labels have no gapbetween them and have square-corners. In at least some embodiments, thelabel assembly 100 may be perforated to allow the labels to beseparated. More particularly, the liner 108 may be perforated at regionswhich demarcate the labels. That is, the perforations may separate onelabel 110 from another.

Referring now to FIG. 3, a top view of an alternate label assembly isillustrated. The label assembly of FIG. 3 has similar construction tothat in FIGS. 1 and 2, except that the top layer 102 is die cut insteadof being butt cut. Die cut labels 110 may have rounded corners and alsohave spacing between each label 110. That is, there is a gap separatingone label 110 from another. Like the butt cut label assembly, the diecut label assembly may also include perforations separating one label110 from another. The perforations may be provided midway between thelabels (i.e., between midway between ends of each gap separating thelabels).

As illustrated in FIGS. 1 to 3, the label assembly 100 may be providedin the form of a flat sheet. The flat sheet may, for example, beconfigured for insertion within a sheet-feed printer. For example, theflat sheet may be 8.5″×11″, or another standard paper size. In suchembodiments, the label assembly 100 may include a plurality of labels.In other embodiments, the label assembly 100 may be provided in the formof a roll. For example, the roll of labels may be configured forinsertion within a printer that is adapted to receive a roll. Forexample, the labels may be scale labels that are used in a scaleprinter, such as a deli scale printer. A scale printer is a printer thatis connected to a scale to allow for customized printing based on theweight measured at the scale.

Referring now to FIG. 4, in some embodiments, the label assembly mayinclude only a single label. More particularly, a label assembly havinga top layer 102 that includes a single label 110 may be provided. Thetop layer 102 contacts the adhesive 108 as described above and the liner108 contacts the other side of the adhesive as also described above.

The labels 110 that are described herein may be applied to a package byattaching the label to the body of the package. For example, the labelmay be applied to a box, plastic wrap, Styrofoam™, deli wrapping paper,etc. More particularly, to apply the label to the package body, theliner 108 is removed from the label 110 to expose the adhesive and thelabel 110 is applied to the package body using the adhesive. In usingthe label in this way, a package having a label of the type describedherein is provided. For example, the label includes a top layer having afront side and a back side and a repositionable adhesive covering theentirety of the back side of the top layer. The label is applied to thepackage body such that the package body directly contacts therepositionable adhesive to sandwich the repositionable adhesive betweenthe top layer and the package body.

Notably, traditional label manufacturing techniques are not well-suitedfor manufacturing a label 108 or liner 108 having at least some of thefeatures described herein. As described in the background section above,traditional techniques use paper that has been manufactured to have afinish that prevents liquid from being absorbed into the paper. Forexample, traditional techniques may use a paper that has a smooth,machine finished surface. This is used, at least in part, to prevent theadhesive, which is applied as a liquid to the liner as part of thetransfer coating process, from soaking into the liner. Since the machinefinish also prevents absorption of the silicone, the silicone is layeredon the paper forming the liner when the liner is manufactured usingtraditional techniques. Recycling facilities typically identify suchlayering during sorting and sort the products containing the layer ofsilicone as non-recyclables.

A method 500 for manufacturing a label assembly (and a liner) will nowbe described with reference to FIG. 5, which illustrates a flowchart ofthe method 500.

At operation 502, a liner 108 is formed by coating a paper withsilicone. In at least some embodiments, the silicone is applied at acoat weight of less than 0.5 lb/ream. In some embodiments, the coatweight of the silicone may be less than 0.3 lb/ream. The coat weight maybe greater than 0.15 lb/ream. In some embodiments, the coat weight ofsilicone may be approximately 0.22 lb/ream.

The paper may be of sufficient density to prevent tearing of the liner108 during removal. In at least some embodiments, the liner isconstructed of a paper having a paper density between 50 and 150 gramsper square meter. In one embodiment, uncoated 75 GSM paper is used.

The silicone is applied to a surface of the paper that is not processedto have a machine finish or gloss. For example, the silicone may beapplied to a surface that is porous, having an absorbency similar tostandard copy paper. The surface that the silicone is applied to isnon-finished and non-glossy. In some embodiments, the paper that thesilicone is applied to is standard copy paper. The side of the paperthat the silicone is not applied to (i.e. the side that is opposite theside where the silicone is applied) may have a glossy finish, or may nothave a glossy finish.

The silicone may be applied to the paper in liquid form; for example,with a roller. In other embodiments, the silicone may be sprayed ontothe surface of the paper.

After the silicone is applied to the paper, it may be cured at operation504. For example, in some embodiments, the silicone is cured usingultraviolet (UV) lamps. In some embodiments, the silicone may be awater-based silicone which is cured by drying the silicone using adryer.

At operation 506, an adhesive 106 is applied directly to the bottom ofthe top layer 102. That is, the adhesive 106 is applied directly to theface sheet of the label 110. In contrast to traditional techniques, themethod 500 of FIG. 5 does not rely upon a transfer coating process toapply the adhesive 106 to the label 110. Rather, the adhesive 106 isapplied directly to the label. For example, the adhesive may be appliedto the top layer 102 of the label with a roller or sprayer.

The top layer 102 may be of the type described above and the adhesivemay also be of the type described above.

While FIG. 5 illustrates the application of the adhesive 106 to the toplayer 102 as occurring after the paper is coated with silicone (atoperation 502), in practice, the ordering of these steps may bedifferent. In some embodiments, these steps may be performed inparallel.

The adhesive may be applied in liquid form and, at operation 508, thetop layer 102 and the adhesive 106 are passed through a dryer to removemoisture from the adhesive.

At operation 510, the top layer 102 is laminated to the liner 108. Moreparticularly, the adhesive provided on the top layer is brought intocontact with the liner 108, causing the liner 108 to adhere to the toplayer using the adhesive. Since the liner 108 has been treated withsilicone, it can easily be removed from the top layer and adhesive. Theside of the liner 108 that has been coated with silicone is the sidethat is brought into contact with the adhesive. Thus, the side of theliner 108 that contacts the adhesive does not have a machine finish orgloss.

In some embodiments, after lamination further operations may beperformed to further process the label assembly. For example, the labelassembly may be further processed by cutting the top layer into aplurality of regions, each associated with a separate label. The cuttingmay include die cutting or butt cutting or sheeting. Sheeting producesrectangular labels with square corners that are sheeted individually.

Furthermore, in at least some embodiments, the liner may be perforatedto create a plurality of regions, each associated with a separate label.

While the embodiments described herein have generally describedpaper-based top layers 102, in other embodiments, the top layer 102 maybe polyethylene terephthalate (PET) based or may be constructed of otherfilms and coated papers of various thicknesses. For example, in someembodiments, the top layer 102 may be PET-based to allow for improvedperformance in wet environments (e.g., where the label is to be appliedto a bottle).

Certain adaptations and modifications of the described embodiments canbe made. Therefore, the above discussed embodiments are considered to beillustrative and not restrictive.

What is claimed is:
 1. A method of preparing a liner for a labelassembly to allow the liner to be detachably coupled to a top layer ofthe liner assembly with a permanent adhesive, the method comprising:applying a coat of silicone to a paper at a side of the paper that doesnot have a machine finish or gloss finish and is otherwise uncoated; andcuring the silicone.
 2. The method of claim 1, wherein the paper has asilicone coat weight of 0.5 lb/ream or less measured at a treatmentsurface of the paper.
 3. The method of claim 2, wherein the siliconecoat weight is 0.3 lb/ream or less measured at a treatment surface ofthe paper.
 4. The method of claim 2, wherein the silicone coat weight isgreater than 0.15 lb/ream measured at a treatment surface of the paper.5. The method of claim 2, wherein the silicone coat weight isapproximately 0.22 lb/ream measured at a treatment surface of the paper.6. The method of claim 1, wherein the paper is bond paper.
 7. The methodof claim 1, wherein the silicone is applied as a fiber coat directly tofibers of the paper.
 8. The method of claim 1, wherein the liner isconstructed of a paper having a paper density greater than or equal tofifty grams per square meter.
 9. The method of claim 1, wherein theliner is a single layer liner.
 10. The method of claim 1, wherein theliner is perforated at regions which demarcate labels of the labelassembly.
 11. A release liner for detachably coupling to a top layer ofa liner assembly with a permanent adhesive, comprising: paper having afirst side that does not have a machine finish or gloss finish or acoating; and a silicone treatment applied to the first side of thepaper.
 12. The release liner of claim 11 wherein the silicone treatmentis applied as a fiber coat directly to the fibers of the paper.
 13. Therelease liner of claim 11, wherein the paper has a silicone coat weightof 0.5 lb/ream or less measured at a treatment surface of the paper. 14.The release liner of claim 13, wherein the silicone coat weight is 0.3lb/ream or less measured at a treatment surface of the paper.
 15. Therelease liner of claim 13, wherein the silicone coat weight is greaterthan 0.15 lb/ream measured at a treatment surface of the paper.
 16. Therelease liner of claim 13, wherein the silicone coat weight isapproximately 0.22 lb/ream measured at a treatment surface of the paper.17. The release liner of claim 8, wherein the paper is bond paper. 18.The release liner of claim 11, wherein the release liner is constructedof a paper having a paper density greater than or equal to fifty gramsper square meter.
 19. The release liner of claim 11, wherein the releaseliner is a single layer liner.
 20. The release liner of claim 11,wherein the release liner is perforated at regions which demarcatelabels of the label assembly.